$ { \left[\begin{array}{r}{4} \\ {1} \\ {-1}\end{array}\right]+\left[\begin{array}{r}{0} \\ {4} \\ {4}\end{array}\right] = {?} } $
Solution: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{r}{4}+{0} \\ {1}+{4} \\ {-1}+{4}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{r}{4} \\ {5} \\ {3}\end{array}\right]}$